L1 Adaptive Control Augmentation for the Longitudinal Dynamics of a Hypersonic Glider

The descent longitudinal trajectory control methodology of a hypersonic glider to carry out a pullup maneuver is presented. A dynamic pole placement controller is implemented as the baseline controller. The baseline controller is augmented with an adaptive controller to cancel out the matched and unmatched uncertainties. The differences between the pole placement and the augmented pole placement controller are presented in terms of performance with the help of Monte Carlo simulations. The dynamic pole placement controller is shown to have robustness in the presence of time-invariant and time-varying errors in the aerodynamic coefficients, control surface, and gravimetric uncertainties. The augmented controller improves the performance of the baseline controller in the presence of these uncertainties. This is concluded with a reduction in the tracking error norm and the control surface norm, which is the energy of the deviation between the reference and real control signal; . The use of the adaptive controller, however, reduces the time delay margin of the system. The contribution of this paper lies in the application and determination of the performance of a piecewise constant adaptive augmentation setup to a nonminimum phase linear time-varying state feedback system.